Lubricating oil



Patented Apr. 24, 19 45 I l Zlfilfifi 2,374,559 tunmca'rmson.

5 Claims. (c1. 252-48) 'This invention relates to an improved lubricatsurfaces, particularly bearing surfaces, which reing adapted for use'in internal combustion ensuits from the corrosive action of the mineral gines and particularly to a lubricating oil having lubricating oil.

' one or 'more additives incorporated therein, It is, the object of the present invention to It is generally conceded that in the recent deprovide a mineral oil composition-which possesses velopment of internal combustion engines, and the above-mentioned detergent. and anti-oxidant particularly engines, designed for heavy-duty or anti-corrosive properties by incorporating in a service, the increase in operating temperatures, mineral lubricating oil a novel additive ingredient together with the reduction of clearances and the of multi-functional activity.

use of hard bearing alloys, such as copper-lead, A further object of, this invention is to provide 'cadmium-silver, ,etc., have set up such severe a mineral oil. composition possessing detergent operating conditions as to necessitate an improveproperties and enhanced anti-oxidant or antiment in' the, highly solvent-refined mineral oils recorrosive properties by combining with the abovefined for use as crankcase lubricants. These rigmentioned multi-functional additive an auxiliary crous operating conditions, which are most prevadditive ingredient and incorporating the comalent in Diesel and gasoline engines used in heavy bination in a mineral lubricating oil.

duty bus and tractor service, have seriously ache in e t n s as d p n the discovery 0 centuated such problems as corrosion, oxidation. a novel class of multi-functional additives which and resin formation in the solvent-refined minmay be broadlyidescribed as oil-soluble or oil-miseral lubricating oils with the resultant deleterious cible metal derivatives of alkyl-substituted arylefiect on the efiiciency of the engines. The naoxy or arylthio-oxy sulfides. It has been found ture and extent of these problems depend upon that Whensmall proportions of a compound withthe conditions of operation of the particular enin the scope of the above general class are blended gine type, the type and extent of refinin of the 'with a mineral lubricating oil; a mineral oil combase oil'used, and numerous other factors. position is formed possessing excellent detergent The tendency of mineral lubricating oils to deand anti-oxidant or anti-corrosive properties. posit gums, resins, soot and varnish-like materials Specifically, the compounds of the present inabout the valves, rings, pistons, cylinders and vention may be described as oil-soluble or oilother engine parts can be largely overcome by miscible metal salts-of the class of compounds the addition of certain types of additive ingredihaving the structure:

' 'ents which possess detergent properties when dis- R solved or dispersed in mineral lubricating oils. By

detergent properties is meant not only that property which aids in dispersing, removing or purgl ing foreign materials which accumulate on the 3 surface ofthe engine parts, but also thatpropin which R and R represent alkyl, aralkyi, cycloerty which prevents the accumulation or deposialkyl or naphthenyl radicals, the alkyl portion of 'tion of such materials, as distinguished from solwhich contains at least 5 carbon atoms. .R. is vent action upon these accumulations or depreferably the same as R; but may also be a difposits. 40 ferent radical, within the above'group. X and In addition thereto the added tendency of'these. -X' represent either an oxygen or sulfur atom, and oils'to corrode-the metal surfaces with which the vary, 2 are integers of 1 .or more. n and yare lubricating oil comes in contact may be overcome ,usually 1, 2, 3 or 4, while 2 is usually 1, 2, or 3'. or reduced by the addition of additive compo- Either or both of the aromatic nuclei diagram.- nents which possess anti-oxidant 'or anti-cormatically shown maybe substituted by a naph rosive properties when dissolve'd'or dispersed in thy], anthracyl or other condensed aromatic mineral lubricating oils... These anti-oxidant or nuclei. The positions of the substituent inthe anti-corrosive properties are meant to includeall formula'are purely diagrammatic and may be such properties which-effect a, reduction or elimiconnectedto any position in the aromatic nucleinatiomof weight loss of the lubricating metal The sulfide bond between'the nuclei represented by S1: may be any one of the following structural groups.

The metallic derivatives of this class bf compounds, in which the hydrogen of the ydroxyl (OH) or sulphydryl group (SH), illust ated above as XH and X'H respectively, is replaced by a metal, include any of the following metals or combinations thereof: sodium, potassium, calcium, barium, strontium, magnesium, aluminum,

peared as a dark oil, were obtained.

tin, iron, cobalt, nickel, copper, manganese and chromium. These derivatives also'include the partial derivatives wherein the hydroxyl or sulphydryl groups are only partially converted into their metallic salts as followszj (where M is a' monovalent metal), and

wC a I Ry 'y (where M is a divalent metal).

As illustrative of the specific compounds whose oil-soluble metallic derivatives fall within the scope of ,the' present invention, the. followin list of compounds is presented:

The following examples illustrate suitable methods for preparing the above-described multi-fimctional additives:

Example I 34 grams of sulfur monochloride (0.25 mol) in a carbon disulfide solution were added to a car- 135 grams of sulfur monochloride in an equal steam bath at -80 the solvent and residual hydrogen chloride. 152' bon disuliide solutionof 138 grams of tridecyl phenol (0.5 mol) with stirring. After the spontaneous evolution of hydrogen chloride had ceased, the reaction mixturerwas heated on a C. for two days to evaporate grains of di (tridecylphenol) disulflde, which ap- Exampleill 75.4 grams of di (tridecylphenol) disulfide were I added-to a solution of calcium ethylate made from 8.8 grams of calcium in 100 cc. absolute alcohol. The mixture was stirred for two hours at -80 C., then freed of solvent by heating at -85 C. in vacuo. The residual. calcium salt was an oil-soluble dark, sticky mass, which gave the following analysis: a i

- [Per cent Ash 18.6 Sulfur -si 6.9 Free sulfur 0.86

Example 111 To 700 grams of polymer phenol (hydroxyl No. 166), prepared by the alkylation of phenol with a mixture of olefins (bromine'No. 129), with'a boiling range of 350-450" F., which wasseparated from the raw polymer fraction from the cata lytic polymerization of gasoline, was added an equal volume of carbon disulflde. A solution of volume of carbon disulfide' was added portionwise to the solution of polymer phenol at room temperature while stirring. The resulting solu tion was maintained at room temperature until the spontaneous evolution of hydrogen chloride gas had ceased, then warmed gently on a. steam bath to evaporate oiT the solvent, unreacted sul fur monochloride, and residual hydrogen chloride. The resulting di .(Dolymer phenol) disulfide appeared as a. dark residue and gave the following analysis: Per cent, Total sulfur 8.13 Freesulfur l Example IV 5 In the preparation of a partially converted barium salt of di (polymer phenol) disulfide, grams of di (polymer phenol) disulfide (approx imately 0.135 mol), from Example III, 'were reacted with 11.5 grams of anhydrous barium hy-' droxide (approximately 0.0675 mol) in'the pres-, enoe of 200 cc. of toluene.

The reaction mixture was stirred and heated to reflux under an automatic water separator for four hours, thereafter filtering through cloth and filter-eel. The filtrate then was freed of solvent byheating to 80-90 C.

in vacuo. In the resulting salt it was found that I only one-half of the phenolic "groups was converted to the barium salt. It analyzed 7.62% sulfur and 7.0%barium. I

These compounds have been found to impart excellent detergent and anti-oxidant or anti corrosive properties to a mineral lubricating oil .when they are blended therewith in proportions ranging from 0.1-5.0% by weight. These proportions vary with the particular type 01' min eral oil used and the tended herein are between 0.25 and 2.0% by weight.

An additional featu're of the present invention is the combination of the foregoing multi-Iunctional additives with an auxiliary additive in- Trace purpose for which it is in-' However, the proportions preferred certain Diesel and gasoline engines, which are designed for special heavy duty service, a higher degree of anti-oxidant or anti-corrosive properties is desired, and for this purpose an antioxidant oranti-corrosive improving additive is added with the compounds aforementioned. The class of.compounds which may be used to impart the additional anti-corrosive property may be any one of the generally accepted .sulfurized vanti-chrrosives.

ftive sulfurized anti-corrosive compounds found Among the particularly efl'ec suitable for purposes of the inventionzare the sulfurized esters of oleic-acid, suchas sulfurized ethyl oleatc, sulfurized high boiling gasoline polymers, suchas the sulfurized clay tower polymers, sulfurized fatty oils, such as sulfurized sperm oil, sulfurized wax compounds, such as sulphurized paraffin wax, sulfurized resin derivatives, such as sulfurized abietene, sulfurized tall oil, and

sulfurized terpene hydrocarbons, such as the sulf furized terpinolenes and isomers thereof, which are disclosed and claimed in the copending ap-' plication of Knowles et al., Serial No. 391,468

filed May 2, 1941. The amount of sulfurized compound added to the mineral lubricating oil in combination with the multi-functional additive is usually within the proportion range of 0.5 to 5.0% by weight and preferably between'LO and 3.0%, depending upon the type of lubricatin O used.

Thesesulfurized auxiliary additivesmay be prepared in accordance with the copending applications of Edwin C; Knowles and Frederick ,C. McCoy, Serial Nos. 358,876, 358,877 and 358,878, respectively, all filed September 28, 1940, wherein a light-colored sulfurized material is prepared by the direct action of sulfur to the unsaturated material at app foximately 300 F. in-the presence of water and under pressure of hydrogen sulfide. This pressure, which is at least 50 pounds per square inch, is maintained until all the free sulfur has entered into combination and lasts usual- "ly from one-half to three hours. The sulfurized products formed by this process are directly soluble in a mineral oil and possess the added advantage in that the reaction product is a lightcolored compound as against the usual dark- I colored sulfurized compounds.

As illustrative. of the anti-corrosive properties of a lubricating oil containing either or both of the aforementioned class of compounds, the

results of the following empirical tests are presented. A copper-lead bearing specimen, incased in aspecial non-wear bushing and rotatably mounted on a stainless steel shaft, was.immersed in a glass pot of the oil to be tested. The tested oil was heated to a' controlled temperature of either 250 F. or 350 F. and continuously circulated between the bearing specimen and the shaft for periods of. time varying from two to ten hours. The bearing specimen was weighed before the test and at two-hour intervals and the loss in weight recorded in milligrams. The reference oil which was used throughout this test tion, taken individually..a d in combination, and

the results compared. The metal derivatives tested, unless otherwise noted, are the normal 3 The results of two runs at 250" F. and 350 F., respectively, are presented:

Bearing corrosion -C0pper lead (10 hours) Loss of weight in mg. Oil tested Reference oi l 88, 39 133,185 Recrence o1l-H).5% barium di (tridecyl phenl, l 07,.71 R iiitte't'e au r e:erenceo a e um po ymer-p enphenolate) disulfldc 2, 3 Reference oil+3.0% suliurized sperm oil. l8, 19 1-4. 0 Reference oil-Hl.5% barium d1 (trldecyl phenolate) disulflde+3.0% s u l f 111') z e d sperm oil 2, 3 i4. 20 Reference oil+0.5% barium rii (polymeh' phcnolate) disulflde+3.0% sulfunzcd sperm oil l), U 2). 16 Reference oil-H.57 barium di (polymorpinolonc 0, l 0, 5 Reference c1l+0.5% barium (ll (polymerphenols-ta) disulflde+2.0% sulfurlzed ethyl oleate 0, l 26, 13 Reference oil+0.5% barium (ll (polymorphenolato) disulfide+8.0% sulfurizcd clay tower polymers 0, U 0, l

The res ults obtained by this test indicate the exceptional non-corrosive characteristics of the combination ofbarium di. (polymer-phenolatel disulfide with sulfurized terpinolene and sulfurizedclay tower polymers in. a solvent refined lubricating oil at bothtemperatures of 250 and 350 F.

In order to illustrate the aforementioned detergent properties of the additives of the presen't invention, a test was devised which simulated running the engine at 1800 R. P. M. with a jacket temperature of 212 F., a crankcase temperature of 300F., and with a crankcase ventilation of 0.4 cubic feet of air per minute for twenty-four hours. Then-without cleaning the piston, the oil was changed to the compounded oil containing the proposed additives and the engine operated at 1800 R. P'. M., with a jacket temperature of 315 F., a crankcase temperature of 200 F., and with no crankcase ventilation for twenty-four hours. At the end of the twenty-four hour period, the engine was dismantled, the condition of the piston noted and the oil classified.

The following results were obtained with asolvent-refined, dewaxed Mid-Continent lubricating oil of SAE 30 grade as a reference oil together with this reference oil compounded with the proposed additives:

Lauson detergency test 0i] tested Rating Reference oil...-. Bari Reference oil+3.0% sulfuriaed spcnn oil Fa r Reference oil+3.0% sulfurlzed sperm oil+0.5% barium Falr iii (tridecyl phenolate) disulfide.

' The eflect'of the proposed additives in reducing oil ring sludge is shown by the results of 'a socalled oil ring sludge test. In this test a-CFR Reference oil 3.0% sul- (Cooperative FuelResearc-h) Diesel engine was operated for thirty-six hours at 1200 R. .P, M., witha jacket temperature of 210 F. andta rich. fuel-mixture fed at the rate of 20 cc. per minute to aggravate sludge formation. The runs from the test were first made by using a reference oil,

such as a solvent-refined, dewaxed Mid-Continent lubricating oil SAE 30 grade, and then, upon the same reference oil, compounded with varying proportions of the proposed additives. At the completion of each run the oil rings were taken out and weighed, and the results of the test tabulated as the percentage improvement of the com-' pounded oils over the reference oil as follows:

' Oil ring sludgr'nb test A Reference oil 3.0% sulfurized sperm o n 4% less oil ring sludge than reference oil.

furized sperm oil, 0.5% barium di ,(tridecyl phenolate) disulfide 19%1ess oil ring'sludge than reference oil.

single cylinder Diesel engine operating at 900'.

R. P. M. with a water jacket temperatureof 175 F., and run continuously forperiods of 120 and 240 hours, or until rings are. stuck, as indicated by the. increase in blowby'. The crankcase oil was drained every 60 hours and fresh oil added thereto. At the end of the 120 and 240 hour runs the engine was thoroughly examined and any car- 'bonaceous deposits. lacquer formation; or corrosion characteristics noted. In the present in stance the reference oil used was a solventrefined, dewaxed- Mid-Continent with other additive ingredients, such as pour point depressoraoiliness agents, extreme pressure, addition agents, blooming agents, viscosity index improving agents, colorstabilizers, -etc.,

without departing from the spirit of theinvention. a

Obviously many modifications and variations of the invention, as hereinbefore set forth, may

be made without departing from the spirit and scope thereof and, therefore, only such limita-' tions should be imposed as areindicated in the appended claims.

What we clain'ris:

l. A Diesel lubricant comprising a mineral lubricating oil having incorporated therein 20.25 to 2.0% Icy-weight of an. oil-soluble metal salt of an alkyl phenol sulfide and 1.0 to 3.0% by weight of a sulfurized high boiling gasoline polymer.

2. A lubricating com-position comprising a-mineral lubricating oil having incorporated therein, the combination of (Ll-5.0% by weight of an oilsoluble metal derivative-of an alkyl substituted aryloxy sulfide and (lb-5.0% by weight of a sulfurized hydrocarbon possessing anti-corrosive properties. 1

3. A lubricating composition comprising a mineral lubricating oil and the combination of 0.l5.0% by weight of an oil-soluble metal derivative of a compound of the formula in which R and R'- are radicals selected from the at least 5 carbon atoms, X andx are elements fromthe group consisting of o ygen and sulfur. n, 1/, z are integers of at least 1, and in which the aromatic nuclei are selected from the group consisting ofphenyl, naphthyl. anthr'acyl and other condensed nuclei, and 0.5-5.0% byweight lubricating oil of .o'f a sulfurized hydrocarbo possessing' anti- SAE 30 grade. a .corrosivepropertiea V c i Engine part Reference oil Reference (mlr rphonolsto) Coppzeg-ead bcaringwaight loss: 7 0 0m 0 on N m v 1 Ours 13m! -L- grams. 0 [bk we" r i 24 hours 0.024 grams. No mm, 3, gag, Piston crown: i 12) hours Normal Norms], i .240 hours V Very light carbon. ayi Nos 3 and 4 slight lacquer Nos 5 and fisludgo Nos 1 2 d 3 loan N 1 ours... m c i dteifisit with 'No. 5 sticking and No. a slight oi lacquer. No g g y "9. 240 h rs Nos-1 2 and 3 clean, but No. lring 907 stuck in N 1 2 3 1 ou ring 'groovo. Nos. 4, 5 and fishow lacquer on top on top'oi rings. 1%: am rtize??? slight of ring and signs of sticking. v v 4 Ring grooves: v

1201101118 -"f""' g ya c o i var nish N 5, 3 and 44mm V8 240hours No. 1 hard carbon build-up. Nos. 2, 4, 5 and 6 Same as hours. 08 an 6 3 l black lacquer. N o. 3 tmccof lacquer. i'golf 1" ring has brown Varm sh and other spotted Clean exce t r a" 11 t b S or our g 3% m {amnion a I extending!!! x2 o s: varnish formation ending along 0 i h s 2!, of brown varngh around piston and 3" 2 11 t varnish 1 r :40 our bF-bmwn varnish formation along axis of 3f pis t on. om'lmon i p on. Under piston deposit g Y i 120 hours -L--. 1 Blight trace. 1 2:0 hours Black, granular deposit T Oiiiter:

120 hours s t t s of lint de rln l i t sludge covering mesh 1 V 240 hours urface covered with lint sludge, no mesh visibla- Same as 20 The multi-functional additives of the present invention may further be used injcombination 7s mineral lubricating oil and 4. An improved lubricating oil' cmnprising a the combination of Ll-5.0% by weight of an oil-soluble metal derivative of a compound of the formula:

'- (XE), (x 11).

in which R and R are radicals selected from the group consisting of alkyl, aralkyl, cycloalkyl' and naphthenyl radicals, tne alkyl portion of which contains at least 5 carbon atoms; X and X are elements from the group consisting of oxygen and w gasoline polymer.

in (Ll-5.0% by weight of an oil-soluble metal derivative of a compound of theformula in which R and R are radicals selected from the group consisting of'alkyl, aralkyl, cycloalkyl and naphthenyl radicals, the alkyl portion of which contains at least 5 carbon atoms; X and X are elements from the group consisting of oxygen and sulfur; n, y and z are integers of at least 1, and 0.5-5.-0% by weight of a sulfurized high-boiling JOHN ROBERT MORRIS. RUSH F. MCCLEARY. 

